1. Field of the Invention
The present invention concerns a method of detecting after-running of electrical servomotors, especially electrical servomotors in motor vehicles, with incremental position detection.
2. Prior Art
Methods for detecting after-running of electrical servomotors are known in which evaluation electronics are used to detect position signals of the position indicators and store the states of the incremental position indicators in nonvolatile memory.
A process for position detection of a motor vehicle part driven in two directions by electric motors is known from EP 0 603 506 A2. With the aid of a counter, when the part moves in its two directions, counting pulses of a position indicator are input into the counter in order to reduce or increase the count in accordance with the predetermined movement. After the drive motor is switched off, the pulses supplied from the position indicator are analyzed in their chronological distance from the shutoff time and are associated with a further movement of the counter if the chronological distance of the pulses does not exceed a predetermined measure. When the drive motor is subjected to a polarity reversal the counting direction is associated with the new movement direction only when the distance of the pulses reduces further after the polarity reversal.
In this known process, nothing is disclosed regarding measures that permit a tracking or after-running detection with prior disconnection from the supply voltage and a storage of position data for the subsequent position correction with reconnection to the supply voltage as well as a reduction in the time required for the after-running detection.